000
AXPZ20 KNHC 241519
TWDEP 

TROPICAL WEATHER DISCUSSION     
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC WED JAN 24 2007

TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM 
THE EQUATOR TO 32N...EAST OF 140W. THE FOLLOWING INFORMATION IS 
BASED ON SATELLITE IMAGERY...WEATHER OBSERVATIONS...RADAR...AND 
METEOROLOGICAL ANALYSIS.

BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1500 UTC.

...ITCZ...

ITCZ AXIS IS CENTERED ALONG 4N77W 4N92W 10N106W 5N125W 4N140W. 
SCATTERED MODERATE/ISOLATED STRONG CONVECTION FROM 3N-6N E OF 
80W. ISOLATED MODERATE WITHIN 90 NM OF THE AXIS BETWEEN 82W-96W.

...DISCUSSION...

CLASSIC OMEGA BLOCK IS STUCK OVER THE WATERS N OF 20N WITH A 
RIDGE AXIS ALONG 119W INTO CALIFORNIA/NEVADA...FLANKED BY A DEEP 
CLOSED LOW OVER NW MEXICO NEAR 29N108W AND A MORE PROGRESSIVE 
TROUGH BRUSHING THE AREA ALONG 135W. A NEAR ZONAL SUBTROPICAL 
JET IS POSITIONED ALONG 19N/20N WITH CORE SPEEDS OF 100 
KT...THEN TURNS NE INTO N/CENTRAL MEXICO ON THE SE PERIPHERY OF 
THE CLOSED LOW. A WEAK COLD FRONT HAS MOVED INTO THE FAR NW 
CORNER OF THE AREA FROM 30N137W 28N140W WITH ISOLATED SHOWERS 
WITHIN THE FRONTAL BAND...AND FURTHER WEAKENING IS ANTICIPATED 
DURING THE NEXT 6-12 HRS. OVERALL THE MIDDLE AND UPPER 
ATMOSPHERE ARE FAIRLY SUBSIDENT AND HAS THUS LIMITED THE 
VERTICAL EXTENT OF CLOUD COVER EVEN IN THE ITCZ...AT LEAST W OF 
110W.

FARTHER E...A SURFACE TROUGH EMBEDDED WITHIN THE ITCZ IS LOCATED 
SW OF ACAPULCO FROM 6N109W TO 14N103W AND PROVIDES THE DIVIDING 
LINE FOR WEAK 5-10 KT WINDS TO THE E...AND STRONGER 20 KT NE 
WINDS TO THE W. ALTHOUGH A FEW SHOWERS MAY BE LOCATED NEAR THE 
TROUGH...THIS FEATURE HAS WEAKENED SINCE YESTERDAY IN TERMS OF 
THE ASSOCIATED LOW-LEVEL CONVERGENCE. WINDS OVER THE GULF OF 
TEHUANTEPEC ARE 20-25 KT BUT ARE EXPECTED TO INCREASE TO GALE 
FORCE BY THU MORNING AS HIGH PRES BUILDS OVER THE GULF OF 
MEXICO. PAPAGAYO WINDS WILL REMAIN STEADY 20 KT FOR THE NEXT FEW 
DAYS. WINDS OVER THE GULF OF PANAMA ARE UNEXPECTEDLY 20-25 KT 
ACCORDING TO QUIKSCAT DATA FROM THIS MORNING...AND EXPECT THESE 
WINDS TO CONTINUE UNTIL THU EVENING BASED ON 925 MB WIND 
GUIDANCE FROM THE GFS.

THE CLOSED LOW OVER NW MEXICO IS FORCING A STRONG 125 KT JET 
CORE OF THE SUBTROPICAL JET ACROSS N/CENTRAL MEXICO WITH A 
PROLIFIC BAND OF MID/UPPER LEVEL CLOUDINESS ACROSS MUCH OF THE 
COUNTRY. A STATIONARY FRONT IS DRAPED ACROSS THE MOUNTAINOUS 
TERRAIN FROM NEAR VERACRUZ NW TO DURANGO AND COLD LOW-LEVEL FLOW 
IS BEING FORCED ONTO THE MEXICAN PLATEAU WITH SUB-FREEZING 
TEMPERATURES AND LOW STRATUS E OF THE SIERRA MADRE OCCIDENTALS.

$$
BERG